The Health Department has identified the first 15 restaurants branded with a lowly C since the city’s A-B-C grading system was launched more than three months ago — but more than half of those eateries were caught hiding their lousy grades from customers.

A Post survey found only seven of the C restaurants posted the grade as required by law, with managers at the other eateries claiming they didn’t understand the rules or, seemingly, trying to game the system.

At the Bread & Pastry Cafe in Greenwich Village, which earned a C on Sept. 9 after racking up 41 violation points, a “grade pending” sign hung in the window Wednesday. Restaurants are slapped with a C when inspectors issue 28 violation points or more.

“It’s my choice,” insisted clerk Mohammed Zaman, explaining that the cafe was due for another hearing at which it would get a higher grade.

When The Post inquired with the department, it sent over an inspector on Friday to demand the C be posted.

Zaman complied. He put up the C right next to the “grade pending,” leaving customers scratching their heads.

The grade that greeted patrons last week at Red Curry Thai at 399 Lexington Ave. depended on which day they visited.

Although it received 31 violation points on Aug. 12 to qualify for a C, the restaurant posted a “grade pending” sign until eight days ago, when The Post began making inquiries.

On Monday, at the department’s insistence, the C went up in a prominent spot. But by the time a reporter strolled by on Wednesday at 8 p.m., the “grade pending” was back. Finally, on Friday, the C returned.

Manager Brian Chen maintained he did nothing wrong, claiming the C was always visible in a corner of the window.

In SoHo, Cafe Felix displayed a “grade pending,” even though it racked up 58 violation points on Aug. 19 and 36 in a reinspection on Sept. 14.

Dan Kass, who oversees the restaurant program at the department, defended the new system and pointed out that restaurateurs get two chances to improve their grades before they’re finalized. An establishment that doesn’t get an A the first time is entitled to a second inspection. If it still doesn’t do well, the owner can try to whittle down the points by going before an administrative law judge.

He warned that restaurants that fail to post grades face $1,000 fines.